C++ string.replace()字符替换函数的用法

C++ replace()函数返回string 能放的最大元素个数。（不同于capacity）

size _ type max _ size( ) const;   basic_string <char>::size_type cap, max;   cap

= s.capacity ( );   max = s.max_size ( ); // max=4294967294.  

basic_string::rfind  寻找给定的string。返回找到的第一个string 下标值；如果没找到

则返回npos。

与find 不同的是：rfind 默认从npos 开始找。其他相同。

basic_string::replace  将原string 中的元素或子串替换。返回替换后的string。

#include <iostream>
#include <string>
using namespace std;

int main()
{
  string str1("String handling C++ style.");
  string str2("STL Power");

  cout << "Initial strings:n";
  cout << "str1: " << str1 << endl;
  cout << "str2: " << str2 << "nn";

  // demonstrate replace
  cout << "Replace 8 characters in str1 with str2:n";
  str1.replace(7, 8, str2);
  cout << str1 << endl;

  return 0;
}

 /*
Initial strings:
str1: String handling C++ style.
str2: STL Power

Replace 8 characters in str1 with str2:
String STL Power C++ style.

 */      
   
指定具体位置

#include <iostream>
using std::cout;
using std::endl;

#include <string>
using std::string;

int main()
{
   string string1( "abc edfgh ijk lmno pqr stu vw xyz" );
  
   cout << "Original string:n" << string1 << endl << endl;

   int position = string1.find( "." ); // find first period

   while ( position != string::npos )
   {
      string1.replace( position, 2, "12345;;123", 5, 2 );
      position = string1.find( ".", position + 1 );
   }

   cout << string1 << endl;
               
   return 0;
}  

/*
Original string:
abc edfgh ijk lmno pqr stu vw xyz

abc edfgh ijk lmno pqr stu vw xyz

 */     
insert(), erase(), and replace().

#include <iostream>
#include <string>
using namespace std;
  
int main()
{
  string str1("A");
  string str2("B");
  
  cout << "Initial strings:n";
  cout << "str1: " << str1 << endl;
  cout << "str2: " << str2 << "nn";
  
  str1.insert(6, str2);
  cout << str1 << "nn";
  
  str1.erase(6, 9);
  cout << str1 <<"nn";
  
  str1.replace(7, 8, str2);
  cout << str1 << endl;
  
  return 0;
}